This invention relates to an apparatus for packaging electronic components. In particular, this invention relates to an apparatus for packaging integrated circuits contained in or on a carrier tape, wherein the apparatus includes a carrier tape secured to a packing reel containing a central hub and parallel flanges, wherein the composition of one or more of the components of that packing reel includes a plastic material and a desiccating material and, in addition, preferably includes a copolymer and an electrostatic charge dissipating and/or anti-static material. A humidity indicating system is also preferably secured to the packing reel.
Electronic components, such as integrated circuits (“IC”), are conventionally shipped from a factory to the user in large quantities. To protect these ICs during transportation, they are generally secured in special tubes, trays or to a carrier tape secured to a specialized packing reel. Plastic ICs are susceptible to moisture due to the permeable nature of their plastic composition. It is well known that ICs, which have been contaminated by high levels of moisture, may not be useful. Mechanical failure of such moisture contaminated ICs often leads to the subsequent failure of the device which contains the ICs due to thermal and mechanical stress. Accordingly, exposure of ICs to moisture should be limited.
One specialized type of packaging for ICs, is discussed in U.S. Pat. Nos. 4,971,196, 5,095,626, 5,293,996 and 5,295,297. Each of the packaging containers incorporates a moisture indicator device secured to the inside surface of the packaging container. Specifically, U.S. Pat. No. 5,293,996 discloses a packaging container for integrated circuits containing an observation window. The container is divided into three sections, wherein one of those sections contains a compartment (11) housing a humidity indicator device (16). The humidity indicator device (16) is preferably a humidity indicator card. As best understood the card is merely placed within the compartment for viewing. The composition of the packaging material of the compartment containing the humidity indicator card is a transparent plastic which permits the moisture indicator card to be viewed from outside of the packaging container.
Another form of apparatus for packaging integrated circuits is disclosed by U.S. Pat. No. 5,318,181, which discloses compartmentalized humidity sensing indicators. These humidity sensing indicators are placed on a tape reel and are secured to its inside surface. Other packing or tape reel systems for ICs are disclosed in U.S. Pat. Nos. 5,875,897, 6,206,198 and 6,469,372.
In addition to their susceptibility to moisture, ICs can also be damaged by static electricity. Therefore, it is important that the packaging for such electronic components also be resistant to electrostatic charge. This resistance should be present in the tray or reel on which the ICs are stored as well as in any moisture-proof bag in which the tray or reel is shipped. Packaging systems for ICs, which are resistant to electrostatic charge are disclosed in U.S. Pat. Nos. 5,875,897, 5,136,827 and 4,568,416.
It is well known that electronic components are also sensitive to particles and dust. Therefore, manufacturing and assembly of electronic devices is performed in clean rooms of class 100-10.
Apparatus for packaging and shipping integrated circuits often must include desiccant products because of the sensitivity of the integrated circuits to moisture.
It is also well accepted in industry that integrated circuits can suffer from contamination with volatile organic compounds (VOC) being emitted from some packaging material. To be useful in the industry these materials must show an extremely low concentration of VOC being emitted during the shelf life of the packaged integrated circuits.
As referenced above, integrated circuits are particularly susceptible to moisture and can also be damaged by static electricity. Further, these components are particularly sensitive to dust.
Accordingly, in one process of the prior art, integrated circuits have been packaged for shipping in a carrier tape and packing reel system using a complicated and expensive process which includes at least the following process steps:                a) inserting the integrated circuits into a carrier tape;        a) securing the carrier tape to the packing reel;        c) baking the integrated circuits dry;        d) inserting the packing reel and tape in a moisture and water-proof bag;        e) inserting desiccant bags into the moisture-proof bag;        f) placing a humidity indicator card into the bag; and        g) sealing the bag; and        h) placing the sealed bag into a transport box.An alternative procedure includes at least the following steps:        a) baking the integrated circuits dry separately from the carrier tape and packing reel;        b) inserting the dried integrated circuits into cavities or slots in carrier tape;        c) securing the carrier tape to a packing reel;        d) inserting the carrier tape on the packing reel in a moisture and water-proof bag;        e) inserting desiccant bags into the moisture-proof bag;        f) placing a humidity indicator card into the bag;        g) sealing the bag; and        h) placing the sealed bag in a transport box.        
Yet another alternative procedure includes at least the following steps:                a) inserting the integrated circuits into a carrier tape;        b) baking the integrated circuits dry on the carrier tape;        c) securing the carrier tape to a packing reel;        d) inserting the packing reel and tape in a moisture and water-proof bag;        e) inserting desiccant bags into the moisture-proof bag;        f) placing a humidity indicator card into the bag;        g) sealing the bag; and        h) placing the sealed bag in a transport box.        
In addition to the fact that these processes are complicated, labor-intensive and time-intensive, the integrated circuits are protected from moisture only after the moisture-proof bag is sealed. Thus, the integrated circuits can still absorb moisture at any time from their original baking until the sealing of the bag.
Another disadvantage of the prior art processes is that the integrated circuits are exposed to dust generated from the desiccant bags themselves or the out gassing of VOC.
Yet another disadvantage of prior art process is that the desiccant bags packaged together with the packaging reel in the bag are rather bulky and lead to “humps” on the surface of the bags. These bags can thus not be packaged by being stacked on each other but require an additional packaging component for mechanical stability. This requirement leads to additional packaging material and labor cost.
Accordingly, it is an object of this invention to prepare a carrier tape and packing reel apparatus for packaging electronic components which reduces the level of moisture within the container holding that packing reel during shipment.
These and other objects and features of the present invention will become apparent to those skilled in art from a consideration of the following detailed description, drawings and claims. The description along with the accompanying drawings provides a selected example of the construction of the device and its process of manufacturing to illustrate the invention.